Sam was right about the First Blade taking its toll on Dean on
At the end of
the May 13 episode, "Stairway to Heaven,"
Dean pretty much ruined Team Free Will's chances at beating Metatron when Gadreel offered inside information to them, and Dean attacked the angel without hesitation.
The Mark of Cain and the First Blade have been affecting him in small ways for weeks now, amping up his anger and agression, but in the Season 9 finale next week, it looks like the Blade and Mark will make him addicted to killing. "I get this high, and I need to kill," Dean says in the finale promo. "I really, really need to kill."
Is Gadreel dead? Can Team Free Will beat Metatron without his help? Is Dean too far gone in his addiction to come back?
Watch the promo for the finale below:
The "Supernatural" Season 9 finale airs Tuesday (May 20) at 9 p.m. ET/PT on The CW.